Charge sensors using inverted lateral bipolar junction transistors

摘要

A method for forming a sensor includes forming a base-region barrier in contact with a base substrate. The base-region barrier includes a monocrystalline semiconductor having a same dopant conductivity as the base substrate. An emitter and a collector are formed in contact with and on opposite sides of the base-region barrier to form a bipolar junction transistor. The collector, the emitter and the base-region barrier are planarized to form a level surface opposite the base substrate such that when the level surface is exposed to charge, the charge is measured during operation of the bipolar junction transistor.

主权项

1. A sensing method, comprising:
providing a sensor having a collector, an emitter and a base-region barrier formed as an inverted bipolar junction transistor having a base substrate forming a base electrode to activate the inverted bipolar junction transistor, and a level surface formed by the collector, the emitter and the base-region barrier opposite the base substrate such that when the level surface is exposed to charge, the charge is measured during operation of the bipolar junction transistor; accumulating charge at or near the level surface; and activating the base substrate as a base electrode to enable the bipolar junction transistor to measure a dose or number of interactions which is proportional to the accumulated charge.